diff --git a/src/js/assignJS.js b/src/js/assignJS.js
index 73511017d46162f64bf08ef1e8e1c036f34e8802..cfad1dae9d09b21c20308f1eeb3543cd6f343236 100644
--- a/src/js/assignJS.js
+++ b/src/js/assignJS.js
@@ -8,7 +8,7 @@
 globalThis.assignJob = function(slave, job) {
 	"use strict";
 	let r = "";
-	let oldJob = slave.assignment;
+	const oldJob = slave.assignment;
 
 	// handle non-exclusive pseudo-assignments as special cases
 	if (job === Job.PIT) {
@@ -402,6 +402,7 @@ globalThis.assignJob = function(slave, job) {
 			break;
 	}
 
+	V.JobIDMap[oldJob].delete(slave.ID);
 	V.JobIDMap[slave.assignment].add(slave.ID);
 
 	if (!assignmentVisible(slave) && Array.isArray(V.personalAttention)) {